1. Field of the Invention
The present invention generally relates to a concave for an agricultural combine and, more particularly, is concerned with a concave with an array of longitudinally notched spaced apart threshing elements that reduce concave plugging and enable more effective threshing.
2. Description of the Prior Art
Rotary combines have a rotary crop processing unit that threshes and separates the grain from the harvested crop material. The rotary crop processing unit is formed by a rotor radially surrounded by a casing. The rotor and casing together define an inlet section, a threshing section and a separating section. As disclosed in U.S. Pat. No. 6,193,604 to Ramp et al., the bottom of the casing has a concave under the threshing section for threshing the crop material and a separating grate under the separator section for separating the grain from the threshed crop material. The inlet section pulls the harvested crop material from a front crop gathering unit into the threshing section. The threshing section threshes the crop material and then feeds the threshed crop material to the separator section.
As shown in the Ramp et al. patent, the concave is provided with a combination of threshing elements in the form of straight bars square in cross-section that are spaced apart from one another with wires between the bars. The objective of this combination is to restrict the flow of crop material so as to enhance threshing of the crop material in the threshing section. However, under corn crop conditions, a tendency frequently develops for crop material flow to be restricted too much by corn shucks getting hung up on the bars and catching on the wires, resulting in plugging of the concave. One solution tried thus far has been to change the threshing elements of the concave to round bars with no wires. But now a tendency frequently develops under some crop conditions, other than corn, for too little restriction of crop material flow such that the other crop materials are not threshed effectively, resulting in overloading of the separator section.
Consequently, a need remains for innovation that will provide a solution to the aforementioned problems.